Expandable spinal implant system with a biased tip and method of using same

ABSTRACT

An expandable spinal implant includes a distal projection extending from only one side of the implant, ending in an anterior tip, the anterior portion and anterior tip defining an elongated distal end hook, which is wider than the proximal end. The distal end hook rotates around the spinal cord, aligning the implant with a desired pathway, then inserts into place in the disc space between the vertebrae. The elongated widened distal end hook provides a TLIF approach, distributes loads, provides anterior rim engagement, and creates lordosis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. application Ser. No.16/295,714, filed Mar. 7, 2019; which is a divisional of U.S.application Ser. No. 15/340,770, filed Nov. 1, 2016; all of which areincorporated by reference herein.

TECHNICAL FIELD

The present disclosure generally relates to medical devices for thetreatment of musculoskeletal disorders, and more particularly to asurgical system that includes an expandable spinal implant, systems forimplanting an expandable spinal implant, and a method for treating aspine.

BACKGROUND

Spinal disorders such as degenerative disc disease, disc herniation,osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvatureabnormalities, kyphosis, tumor, and fracture may result from factorsincluding trauma, disease and degenerative conditions caused by injuryand aging. Spinal disorders typically result in symptoms including pain,nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercisecan be effective, however, may fail to relieve the symptoms associatedwith these disorders. Surgical treatment of these spinal disordersincludes fusion, fixation, correction, discectomy, laminectomy andimplantable prosthetics. As part of these surgical treatments, spinalconstructs, such as, for example, bone fasteners, spinal rods andinterbody devices can be used to provide stability to a treated region.For example, during surgical treatment, interbody devices may beintroduced to a space between adjacent vertebral bodies (the interbodyspace) to properly space the vertebral bodies and provide a receptaclefor bone growth promoting materials.

More recently, interbody devices have been introduced that provideadditional capability beyond static spacing of the vertebral bodies. Forexample, some devices have expansion capability such that the implantmay be introduced to the interbody space in a collapsed state and thenexpanded to produce additional spacing and, in some cases, introduce orrestore curvature to the spine by expanding selectively on only one endor portion of the implant. However, many existing expandable interbodydesigns utilize internal mechanisms that may inhibit the introduction ofbone growth promoting material into the interbody implant by a surgeonafter the implant is expanded.

An additional problem exists related to subsidence of spinal surfacesdue to existing interbody devices having inadequately-sized load-bearingsurfaces. In the case of expandable devices, the loads on theload-bearing surfaces, including loads generated during expansion of theimplant, are often significant. An expandable implant with relativelylarge surface areas is needed to bear the loads, including the loadsgenerated during implant expansion, in an attempt to avoid a need forfollow-on surgery due to subsidence of spinal surfaces.

The present invention seeks to address this and other shortcomings inthe existing art.

SUMMARY

In one embodiment, an expandable spinal implant is provided deployablebetween a collapsed position and an expanded position in a disc spacebetween upper and lower vertebral bodies. The implant includes a framecomprising a proximal wall, lateral walls, and a distal wall, whereinthe proximal wall defines a proximal aperture and the distal walldefines a distal aperture. The implant also includes a plug movablydisposed in the distal aperture of the frame and first and secondendplates operably engaged with the frame and configured to expandoutward from the frame when the plug is moved in a distal directionrelative to the frame, each of the first and second endplates includingrespective first and second lateral walls and respective distal ends.

In one alternative embodiment a system is provided including anexpandable spinal implant and an insertion instrument. The insertioninstrument comprises a cannulated outer shaft and a driver shaftremovably and rotatably disposed within the cannulated outer shaft. Theexpandable spinal implant comprises a frame with a proximal wall and adistal wall, wherein the proximal wall defines a proximal aperture andthe distal wall defines a distal aperture. The proximal wall of theframe is configured to receive a distal end of the cannulated outershaft for manipulating the expandable spinal implant. The expandablespinal implant also comprises a movable plug disposed in the distalaperture of the frame, wherein the plug comprises an interfaceconfigured to be operably engaged by a distal end of the driver shaft tomove the plug relative to the frame. The expandable spinal implant alsocomprises first and second endplates engaged with the frame andconfigured to move relative to the frame when the plug is moved by thedriver shaft of the insertion instrument. The driver shaft is alsoconfigured to be removable from the cannulated outer shaft of theinsertion instrument such that after the plug has been moved distallyrelative to the frame, a bone growth promoting material may beintroduced into the frame through the cannulated outer shaft of theinsertion instrument.

In one alternative embodiment, each of the first and second endplatesinclude an anterior portion projecting from the first and second lateralwalls at the respective distal ends thereon. The projecting anteriorportions increase the surface area of the respective endplates, and endin respective anterior tips. When the implant is in the collapsedposition, the anterior portions and the anterior tips define a distalend hook portion. In addition, when the implant is in the collapsedposition, the first endplate distal end and the second endplate distalend define a distal end beveled portion. The distal end hook portion hasa greater width than the proximal end of the implant. The distal endhook portion is configured, upon insertion of the implant into the discspace, to hook at least partially around the vertebral foramen, therebyavoiding interference with the spinal cord, and other neural elementslocated within the vertebral foramen. The distal end hook portion isfurther configured, upon insertion into the disc space, to rotate to aTLIF/transverse pathway. The implant is now positioned to be inserted tothe anterior apophyseal rims of each of the upper and lower vertebralbodies. Upon expansion of the implant, the distal hook end portion andthe distal beveled end portion engage substantially the entire anteriorapophyseal rim of each of the upper and lower vertebrae. Rows of teethprovided on the first endplate and on the second endplate preventinadvertent backing out of the implant from the anterior apophysealrims. The additional surface area and the additional width of at leastthe distal end hook portion enables the endplates to bear significantlygreater loads applied to the implant by the upper and lower vertebrae.The distal end hook configuration enables a single implant to bepositioned across the midline of the disc space, a single implant to bepositioned spaced laterally to one side of the midline of the discspace, or a first implant to be positioned spaced laterally to one sideof the midline of the disc space and a second implant to be positionedspaced laterally to the opposite side of the midline of the disc space.

In one embodiment, the distal beveled end surface connects to thelateral walls of the endplates opposite the position of the distal endhook portion via a curved portion. The curved portion allows the implantto achieve increased lateral contact with bone close to the anteriorapophyseal rim.

In some embodiments, various other implants, systems and methods aredisclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further informed by the specific descriptionaccompanied by the following drawings, in which:

FIG. 1 is a perspective view of one embodiment of an expandable spinalimplant system in a closed configuration in accordance with theprinciples of the present disclosure;

FIG. 2 is a perspective view one embodiment of an expandable spinalimplant system in an open configuration in accordance with theprinciples of the present disclosure;

FIG. 3 is a perspective view of the components shown in FIG. 1 but withone endplate removed to show inner structures of a closed expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 3A is a perspective view of an endplate component in accordancewith the principles of the present disclosure;

FIG. 4 is a perspective view of the components shown in FIG. 1 but withone endplate removed to show inner structures of an open expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 5 is a perspective view of one embodiment of an expandable spinalimplant system in a closed configuration in accordance with theprinciples of the present disclosure;

FIG. 6 is a perspective view one embodiment of an expandable spinalimplant system in an open configuration in accordance with theprinciples of the present disclosure;

FIG. 7 is a perspective view of the components shown in FIG. 5 but withone endplate removed to show inner structures of a closed expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 8 is a perspective view of the components shown in FIG. 6 but withone endplate removed to show inner structures of an open expandablespinal implant system in accordance with the principles of the presentdisclosure;

FIG. 9 is a perspective view of the components of an expandable spinalimplant system including an insertion instrument engaged with anexpandable spinal implant in accordance with the principles of thepresent disclosure;

FIG. 10 is a perspective view of the components shown in FIG. 9 alsoshowing a driver shaft extended through the cannula and in engagementwith the plug;

FIG. 11 is a perspective view of the components shown in FIG. 9 alsoshowing a driver shaft extended through the cannula and in engagementwith the plug to expand the endplates relative to the frame;

FIG. 12 is a perspective view of the components shown in FIG. 9 alsoshowing the driver shaft removed from the cannula;

FIG. 13 is a top view of one embodiment of an expandable spinal implantsystem as used in a PLIF surgical procedure in accordance with theprinciples of the present disclosure;

FIG. 14 is a perspective view of the components shown in FIG. 13 as usedin a PLIF surgical procedure in accordance with the principles of thepresent disclosure;

FIG. 15 is a top view of one embodiment of an expandable spinal implantsystem as used in a TLIF surgical procedure in accordance with theprinciples of the present disclosure;

FIG. 16 is a perspective view of the components shown in FIG. 15 as usedin a TLIF surgical procedure in accordance with the principles of thepresent disclosure;

FIG. 17 is a perspective view of the components shown in FIG. 15 as usedin a TLIF surgical procedure in accordance with the principles of thepresent disclosure;

FIG. 18 is a perspective view of one embodiment of an expandable spinalimplant system with a single movable endplate and wherein the frame maybe substantially integral with at least one endplate;

FIG. 19 is a perspective view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion;

FIG. 20 is a top view of one embodiment of an expandable spinal implanthaving an anterior projection and an anterior tip defining a distal endhook portion;

FIGS. 21 and 22 are perspective views depicting an initial insertionpath into a disc space of one embodiment of an expandable spinal implanthaving an anterior projection and an anterior tip defining a distal endhook portion;

FIG. 23 is a perspective view depicting an insertion path into a discspace of one embodiment of an expandable spinal implant having ananterior projection and an anterior tip defining a distal end hookportion hooking around a vertebral foramen of a vertebral body;

FIG. 24 is a perspective view depicting a continued insertion path intoa disc space toward an anterior apophyseal rim of a vertebral body ofone embodiment of an expandable spinal implant having an anteriorprojection and an anterior tip defining a distal end hook portion;

FIG. 25 is a perspective view depicting one embodiment of an expandablespinal implant having an anterior projection and an anterior tipdefining a distal end hook portion, positioned between upper and lowervertebral bodies, expanding toward an expanded position;

FIG. 26 is a perspective view depicting one embodiment of an expandablespinal implant having an anterior projection and an anterior tipdefining a distal end hook portion positioned on a lower vertebral body,expanding toward an expanded position;

FIG. 27 is a perspective view of one embodiment of an expandable spinalimplant, in a collapsed position, having an anterior projection and ananterior tip defining a distal end hook portion, includingbackout-prevention portions defined on the upper endplate;

FIG. 28 is an upper view of one embodiment of an expandable spinalimplant, in a collapsed position, having an anterior projection and ananterior tip defining a distal end hook portion, includingbackout-prevention portions defined on the upper endplate;

FIG. 29 is a perspective view of one embodiment of an expandable spinalimplant, in an expanded position, having an anterior projection and ananterior tip defining a distal end hook portion, includingbackout-prevention portions defined on the upper endplate;

FIG. 30 is a perspective view of one embodiment of an expandable spinalimplant having an anterior projection, an anterior tip defining a distalend hook portion, and an arcuate portion at the distal end opposite thedistal end hook portion;

FIG. 31 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion;

FIG. 32 is a perspective view is a perspective view of one embodiment ofan expandable spinal implant having an anterior projection and ananterior tip defining a distal end hook portion;

FIG. 33 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion inserted into a disc space with the distal endhook portion proximate the anterior apophyseal rim, and a proximal endof the implant proximate the vertebral foramen;

FIG. 34 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion being inserted into a disc space;

FIG. 35 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion being inserted into a disc space, with thedistal end hook portion hooking around the vertebral foramen, therebyavoiding contact with at least the spinal cord;

FIG. 36 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end being inserted into a disc space, with the distal end hookportion rotating to a TLIF/transverse pathway;

FIG. 37 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion inserted into the disc space to a positionproximate the apophyseal rim, and crossing over the midline of the discspace;

FIG. 38 is an upper view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion inserted into the disc space and spacedlaterally away from the midline of the disc space;

FIG. 39 is an upper view of two expandable spinal implants inserted intoa disc space, each implant having an anterior projection and an anteriortip defining a distal end hook portion inserted into the disc space andspaced laterally away from the midline of the disc space;

FIG. 40 is a perspective view of one embodiment of an expandable spinalimplant having an anterior projection and an anterior tip defining adistal end hook portion in an orientation that is reversed from theorientation depicted in previous embodiments; and

FIG. 41 is an upper view of the expandable spinal implant of FIG. 40being inserted into the disc space toward the apophyseal rim.

DETAILED DESCRIPTION

The exemplary embodiments of the surgical system and related methods ofuse disclosed are discussed in terms of medical devices for thetreatment of musculoskeletal disorders and more particularly, in termsof an expandable surgical implant system that may include an expandablespinal implant, an insertion instrument and/or a method for treating aspine.

In some embodiments, the present system includes an expandable spinalimplant system suitable for insertion from a direct posterior (sometimesreferred to as PLIF procedures) in pairs or singularly and thenexpandable at a distal end in order to impart and/or augment a lordoticcurve of the spine. In some embodiments shown herein, the expandablespinal implant system may also be configured for use in oblique,postero-lateral procedures and/or transforaminal lumbar interbodyfusions (sometimes referred to as TLIF procedures). Additionally, theframe disclosed in various embodiments may be configured to place amovable plug of the spinal implant in a substantially distal positionwithin the spinal implant so as to clear a proximal volume within theimplant for packing with bone-growth promoting materials after theimplant has been inserted and/or expanded using the various techniquesdescribed herein. The frame and other various spinal implant componentsmay also be configured with one or more sidewalls and/or openings todirect bone-growth promoting material to a selected area of anintervertebral or interbody space after the insertion and/or deploymentof the spinal implant. In some embodiments, the spinal implant systemmay also be provided with a tapered distal tip (as viewed from asuperior or top surface) such that the implant is shaped for insertionfrom an oblique approach and placement at a diagonal across anintervertebral or interbody space.

In some embodiments, the spinal implant system may also be employed torestore and/or impart sagittal balance to a patient by increasing and/orrestoring an appropriate lordotic angle between vertebral bodies at aselected level where the spinal implant is implanted and expanded. Insome embodiments, a pair of such spinal implants may be employed frombilateral PLIF approaches and expanded to differing heights to impartand/or restore both a lordotic angle as well as align the spine in thecoronal plane (so as to treat a scoliotic curvature, for example). Insome embodiments, a single such spinal implant may be employed from apostero-lateral TLIF approach and expanded to differing heights toimpart and/or restore both a lordotic angle as well as align the spinein the coronal plane (so as to treat a scoliotic curvature, forexample). In the various embodiments described, the spinal implantsystem may be useful in a variety of complex spinal procedures fortreating spinal conditions beyond one-level fusions. Furthermore, thespinal implant system described in the enclosed embodiments may also beused as a fusion device with an expandable height for tailoring theimplant to a particular interbody disc space to restore the spacingbetween adjacent vertebral bodies and facilitate spinal fusion betweenthe adjacent vertebral bodies.

In some embodiments, and as mentioned above, the present disclosure maybe employed to treat spinal disorders such as, for example, degenerativedisc disease, disc herniation, osteoporosis, spondylolisthesis,stenosis, scoliosis and other curvature abnormalities, kyphosis, tumorand fractures. In some embodiments, the present disclosure may beemployed with other osteal and bone related applications, includingthose associated with diagnostics and therapeutics. In some embodiments,the disclosed spinal implant system may be alternatively employed in asurgical treatment with a patient in a prone or supine position, and/oremploy various surgical approaches to the spine, including anterior,posterior, posterior mid-line, direct lateral, postero-lateral oblique,and/or antero lateral oblique approaches, and in other body regions. Thepresent disclosure may also be alternatively employed with proceduresfor treating the lumbar, cervical, thoracic, sacral and pelvic regionsof a spinal column. The spinal implant system of the present disclosuremay also be used on animals, bone models and other non-livingsubstrates, such as, for example, in training, testing anddemonstration.

The present disclosure may be understood more readily by reference tothe following detailed description of the embodiments taken inconnection with the accompanying drawing figures, which form a part ofthis disclosure. It is to be understood that this application is notlimited to the specific devices, methods, conditions or parametersdescribed and/or shown herein, and that the terminology used herein isfor the purpose of describing particular embodiments by way of exampleonly and is not intended to be limiting. In some embodiments, as used inthe specification and including the appended claims, the singular forms“a,” “an,” and “the” include the plural, and reference to a particularnumerical value includes at least that particular value, unless thecontext clearly dictates otherwise. Ranges may be expressed herein asfrom “about” or “approximately” one particular value and/or to “about”or “approximately” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. It isalso understood that all spatial references, such as, for example,horizontal, vertical, top, upper, lower, bottom, left and right, are forillustrative purposes only and can be varied within the scope of thedisclosure. For example, the references “upper” and “lower” are relativeand used only in the context to the other, and are not necessarily“superior” and “inferior”.

As used in the specification and including the appended claims,“treating” or “treatment” of a disease or condition refers to performinga procedure that may include administering one or more drugs, biologics,bone grafts (including allograft, autograft, xenograft, for example) orbone-growth promoting materials to a patient (human, normal or otherwiseor other mammal), employing implantable devices, and/or employinginstruments that treat the disease, such as, for example,micro-discectomy instruments used to remove portions bulging orherniated discs and/or bone spurs, in an effort to alleviate signs orsymptoms of the disease or condition. Alleviation can occur prior tosigns or symptoms of the disease or condition appearing, as well asafter their appearance. Thus, treating or treatment includes preventingor prevention of disease or undesirable condition (e.g., preventing thedisease from occurring in a patient, who may be predisposed to thedisease but has not yet been diagnosed as having it). In addition,treating or treatment does not require complete alleviation of signs orsymptoms, does not require a cure, and specifically includes proceduresthat have only a marginal effect on the patient. Treatment can includeinhibiting the disease, e.g., arresting its development, or relievingthe disease, e.g., causing regression of the disease. For example,treatment can include reducing acute or chronic inflammation;alleviating pain and mitigating and inducing re-growth of new ligament,bone and other tissues; as an adjunct in surgery; and/or any repairprocedure. Also, as used in the specification and including the appendedclaims, the term “tissue” includes soft tissue, ligaments, tendons,cartilage and/or bone unless specifically referred to otherwise. Theterm “bone growth promoting material” as used herein may include, but isnot limited to: bone graft (autograft, allograft, xenograft) in avariety of forms and compositions (including but not limited tomorselized bone graft); osteoinductive material such as bonemorphogenetic proteins (BMP) (including but not limited to INFUSE®available from Medtronic plc) and alternative small moleculeosteoinductive substances; osteoconductive materials such asdemineralized bone matrix (DBM) in a variety of forms and compositions(putty, chips, bagged (including but not limited to the GRAFTON® familyof products available from Medtronic plc)); collagen sponge; bone putty;ceramic-based void fillers; ceramic powders; and/or other substancessuitable for inducing, conducting or facilitating bone growth and/orbony fusion of existing bony structures. Such bone growth promotingmaterials (denoted “BG” in some Figures herein) may be provided in avariety of solids, putties, liquids, colloids, solutions, or otherpreparations suitable for being packed or placed into or around thevarious implant 10, 20 embodiments described herein.

The following discussion includes a description of a surgical systemincluding one or more spinal implants, related components and methods ofemploying the surgical system in accordance with the principles of thepresent disclosure. Various alternate embodiments are disclosed andindividual components of each embodiment may be used with otherembodiments. Reference is made in detail to the exemplary embodiments ofthe present disclosure, which are illustrated in the accompanyingfigures. Turning to FIGS. 1-12 , there are illustrated components of asurgical system, such as, for example, an expandable spinal implant 10,20 and associated system including an insertion instrument 30.

The components of expandable spinal implant system 10, 20, 30 can befabricated from biologically acceptable materials suitable for medicalapplications, including metals, synthetic polymers, ceramics and bonematerial and/or their composites. For example, the components ofexpandable spinal implant system (including, but not limited to implant10, implant 20, insertion instrument 30), individually or collectively,can be fabricated from materials such as stainless steel alloys,commercially pure titanium, titanium alloys, Grade 5 titanium,super-elastic titanium alloys, cobalt-chrome alloys, stainless steelalloys, superelastic metallic alloys (e.g., Nitinol, superelasto-plastic metals, such as GUM METAL®), ceramics and compositesthereof such as calcium phosphate (e.g., SKELITE™), thermoplastics suchas polyaryletherketone (PAEK) including polyetheretherketone (PEEK),polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEKcomposites, PEEK-BaSO.sub.4 polymeric rubbers, polyethyleneterephthalate (PET), fabric, silicone, polyurethane,silicone-polyurethane copolymers, polymeric rubbers, polyolefin rubbers,hydrogels, semi-rigid and rigid materials, elastomers, rubbers,thermoplastic elastomers, thermoset elastomers, elastomeric composites,rigid polymers including polyphenylene, polyamide, polyimide,polyetherimide, polyethylene, epoxy, bone material including autograft,allograft, xenograft or transgenic cortical and/or corticocancellousbone, and tissue growth or differentiation factors, partially resorbablematerials, such as, for example, composites of metals and calcium-basedceramics, composites of PEEK and calcium based ceramics, composites ofPEEK with resorbable polymers, totally resorbable materials, such as,for example, calcium based ceramics such as calcium phosphate,tri-calcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate,or other resorbable polymers such as polyaetide, polyglycolide,polytyrosine carbonate, polycaroplaetohe and their combinations.

Various components of spinal implant system 10 may be formed orconstructed material composites, including the above materials, toachieve various desired characteristics such as strength, rigidity,elasticity, compliance, biomechanical performance, durability andradiolucency or imaging preference. The components of expandable spinalimplant system 10, 20, 30, individually or collectively, may also befabricated from a heterogeneous material such as a combination of two ormore of the above-described materials. The components of expandablespinal implant system 10, 20, 30 may be monolithically formed,integrally connected or include fastening elements and/or instruments,as described herein. For example, in some embodiments expandable spinalimplant system 10, 20, 30 may comprise expandable spinal implants 10, 20comprising PEEK and/or titanium structures with radiolucent markers(such as tantalum pins and/or spikes) selectively placed in the implantto provide a surgeon with placement and/or sizing information when theexpandable spinal implant 10, 20 is placed in the spine. The componentsof expandable spinal implant system 10, 20, 30 may be formed using avariety of subtractive and additive manufacturing techniques, including,but not limited to machining, milling, extruding, molding, 3D-printing,sintering, coating, vapor deposition, and laser/beam melting.Furthermore, various components of the expandable spinal implant system10, 20, 30 may be coated or treated with a variety of additives orcoatings to improve biocompatibility, bone growth promotion or otherfeatures. For example, the endplates 140, 150, 240, 250 may beselectively coated with bone growth promoting or bone ongrowth promotingsurface treatments that may include, but are not limited to: titaniumcoatings (solid, porous or textured), hydroxyapatite coatings, ortitanium plates (solid, porous or textured).

Expandable spinal implant system 10, 20, 30 may be employed, forexample, with a minimally invasive procedure, including percutaneoustechniques, mini-open and open surgical techniques to deliver andintroduce instrumentation and/or one or more spinal implants at asurgical site within a body of a patient, for example, a section of aspine. In some embodiments, expandable spinal implant system 10, 20, 30may be employed with surgical procedures, as described herein, and/or,for example, corpectomy, discectomy, fusion and/or fixation treatmentsthat employ spinal implants to restore the mechanical support functionof vertebrae. In some embodiments, expandable spinal implant system 10,20, 30 may be employed with surgical approaches, including but notlimited to: posterior lumbar interbody fusion (PLIF), oblique lumbarinterbody fusion, transforaminal lumbar interbody fusion (TLIF), varioustypes of anterior fusion procedures, and any fusion procedure in anyportion of the spinal column (sacral, lumbar, thoracic, and cervical,for example). Exemplary use of the expandable spinal implant system 10,20, 30 in PLIF and TLIF techniques is shown generally in FIGS. 13-17 .

As shown generally in FIGS. 1-8 , two exemplary embodiments of anexpandable spinal implant 10, 20 are shown (implant 10 is highlighted inexemplary FIGS. 1-4 and implant 20 is highlighted in exemplary FIGS. 5-8). Referring to FIGS. 1 and 2 , expandable spinal implant 10 maycomprise a frame 100 comprising a proximal wall 110 and a distal wall120. The frame 100 may provide a mechanism for placing an expansionmechanism distally in the implant 10 such that, once expanded, theimplant 10 provides ample room nearer the proximal end of the implant(such as at least partially within the frame 100, for example) for thepost-packing of bone growth promoting materials. For example, theproximal wall 110 of the frame 100 may define a proximal aperture 111which may be suitable for receiving at least part of an insertioninstrument 30 through which bone growth promoting material may beintroduced into a proximal portion of the implant 10. Furthermore, thedistal wall 120 of the frame may define a distal aperture 121 (see FIG.2 , for example) that is adapted to receive a plug 130. As describedfurther herein, the plug 130 may be movably disposed in the distalaperture 121 of the frame.

A plunger, syringe, tamp, funnel, pistol grip or hydraulic means mayoptionally be used to advance the material down the insertion instrument30 and into the implant 10 and/or disc space. Another alternative mayinclude passing a tube down the insertion instrument 30. The tube in onepreferred embodiment may be flexible and made of plastic or rubber. Thetube may be prefilled with graft or other material and in one embodimenthas a syringe attached at the end of the tube or alternatively includesa pistol grip, funnel or other means of advancing graft or othermaterial down the tube. The syringe may be prefilled with material. Thetube may be tapered at the distal end to facilitate interfacing theimplant 10. The tube and or the insertion instrument 30 may be flaredout at the proximal end to act as a funnel or to facilitate receiving afunnel, syringe, pistol grip, or other instrument for providing anddelivering the material. The graft also may be loaded into the discspace, where disc material has been removed, prior to the insertion ofthe implant 10, by a tube such as disclosed in U.S. Pat. No. 8,092,464to McKay, incorporated by reference herein in its entirety. The graftloading process described here and below is not necessarily limited tojust use with the disclosed expandable implant but rather could be usedin any fusion procedure or with the use of any intervertebral implant(lateral, oblique, ALIF, PLIF, etc.).

The expandable spinal implant 10 may further comprise a first endplate140 operably engaged with the frame 100 and configured to expand outwardfrom the frame 100 when the plug 130 is moved in a distal direction D(See FIGS. 3-4 ). Furthermore, in some embodiments, the expandablespinal implant 10 may comprise opposing first and second endplates 140,150 as shown generally in FIGS. 1 and 2 . In some such embodiments ofthe expandable spinal implant 10, the second endplate 150 may beoperably engaged with the frame 100 and configured to expand outwardfrom the frame 100 when the plug 130 is moved in a distal direction D.Furthermore, as shown in FIG. 1 , the second endplate 150 may bedisposed about the frame 100 and opposing the first endplate 140,wherein the first endplate 140 and the second endplate 150 extend from aproximal end of the implant 10 to a distal end of the implant 10 (alongthe length L of the implant 10) and at least partially enclose the frame100. A similar structure is also shown in implant 20 of FIGS. 5-8 ,wherein endplates 240, 250 cooperate to at least partially enclose theframe 200 (see FIG. 5 , for example). The various endplates 140, 150,240, 250 may be provided with convex surfaces in multiple planes toconform to adjacent vertebral body endplates (see V1, V2 as shown inFIGS. 14 and 16 ). It should be understood that the surfaces of thevarious endplates 140, 150, 240, 250 could also be constructed with aconvexity in only one plane or without any convexities. Furthermore, thevertebral body V1, V2 contacting surfaces of endplates 140, 150, 240,250 may be provided with various anti-migration and/or osseointegrationfeatures including, but not limited to: ridges, teeth, pores, andcoatings (including but not limited to porous titanium coatings such asthose provided on Capstone PTC™ implants available from Medtronic plc).

FIG. 18 shows an embodiment of an expandable spinal implant 10comprising only a first endplate 140 operably engaged with the frame 100and configured to expand outward from the frame 100 when the plug 130 ismoved in a distal direction D (See FIGS. 3-4 ). In the embodiment ofFIG. 18 , the second endplate 150 may be integrally formed with theframe 100 and/or non-movable relative to the frame 100 such that as theplug 130 is moved distally, only the first endplate 140 (hinged to theframe 100 via pin 154). In such embodiments, the distal head portion 135may be modified to engage the movable first endplate 140 and the staticsecond endplate 150. For example, as shown generally in FIG. 3A, themovable first or second endplate 150 (and/or the complementary endplate140) may comprise a ramped surface 153 upon which ramped surface 136 ofthe distal head portion 135 may bear as the implant 10 is expanded. Theramp 136/153 mechanism may cooperate with a paired lateral post 137 andtrack 145 system (see FIG. 18 ) in order to optimize the opening and/orexpansion of the implant 10.

Referring generally to FIGS. 1-4 , the endplates 140, 150 may beoperably engaged with the frame 100 via a hinge mechanism located nearor on the proximal wall 110 of the frame 100. For example, pins 154 maybe provided that engage corresponding pin apertures 112 defined in theframe 100 such that the endplates are operably engaged with and/orhinged relative to the frame 100 such that the endplates 140, 150 may beexpandable relative to the frame 100 by virtue of the cooperation of thepins 154 and pin apertures 112 as the plug 130 is moved distally Drelative to the frame 100 of the implant 10. Similar hinge mechanismsare also shown relative to the embodiments of FIGS. 7 and 8 comprisingpins 154 engaged with pin apertures 212 to connect frame 200 withendplates 240, 250 in a hinged relationship. While multi-part mechanicalhinges are shown in some of the pictured embodiments, it should beunderstood that other types of hinge and/or connection mechanisms mayalso be used to operably engage the frame 100 with the expandableendplates 140, 150 of the implant. For example, in some embodiments, a“living hinge” may be utilized wherein the endplates 140, 150 are atleast partially integrally formed with the frame 100 at the hinge pointbut with cut-outs or flex points that allow the endplates 140, 150 torotate about the hinge connection. In summary, the frame 100 andendplates 140, 150 may be operably engaged in a number of different waysincluding but not limited to: integral connections, separableconnections, mechanically fixed connections using fastener or adhesives,releasable connections (including, but not limited to keyways andpartially open hinges), and other connection types. In some embodiments,the frame 100 and endplates 140, 150 may be integrally formed usingadditive manufacturing techniques such as 3D printing or sinteringlaser/beam melting, casting, extruding, or machined in an integral formusing subtractive manufacturing techniques from one or more stockmaterials.

In some embodiments, the frame 100 of the expandable spinal implant 10further comprises at least one side wall 102 engaged with the proximalwall 110 and the distal wall 120. As shown generally in FIG. 3 , theside wall 102 or walls 102, 104 may be configured to space the proximalwall 110 and the distal wall 120 along a longitudinal axis (runningsubstantially and/or nearly parallel to the length L) of the expandablespinal implant 10. The side walls 102, 104 may also be configured tocontain bone growth promoting material in a proximal portion of theimplant 10 that may be pre-packed or post-packed into the implant 10 viathe proximal aperture 111. The side walls 102, 104 may cooperate withthe proximal wall 110 and the distal wall 120 to create a four-sidedframe 100 (that may define side apertures as shown in FIGS. 3-4 ). Insome such embodiments, the frame may define internal threads 103configured to cooperate with an outer threaded surface 131 of the plug130 when the plug 130 is positioned generally proximally relative to thedistal wall 120 of the frame 100.

The frame 100 may be especially useful in some embodiments for placingthe plug 130 in a substantially distal position relative to the overalllength L of the implant 10 such that a distal portion of the implant(within a volume substantially encompassed by the frame 100, forexample) may be open and free to be filled (or “post-packed” withbone-growth promoting materials after the implant has been placed in adisc space between vertebral bodies (see, for example, the placement ofimplant 10, between vertebral bodies V1 and V2, shown in FIGS. 14 and 16). As described herein with respect to FIGS. 1, 3, 5 and 7 , the implant10, 20 may comprise or define a length L along a central longitudinalaxis thereof, CL, extending from a proximal end 110 thereof to a distalend 144 thereof. In some such embodiments, the distal wall 120 of theframe may be disposed at least one third (⅓) of the length L (i.e. at aposition spaced distally from the proximal end 110 by a distance W asshown generally in FIGS. 3 and 7 ). In other embodiments the distal wall120 of the frame may be disposed at other fractions of the length L(i.e. at a position spaced distally from the proximal end 110 by adistance Was shown generally in FIGS. 3 and 7 ) including, but notlimited to, at least 1/10, ⅛, ⅕, ¼, ¾, ⅞ and 9/10. In other embodiments,the distal wall 120 of the frame may be disposed at a position spaceddistally from the proximal end 110 by a distance W as shown generally inFIGS. 3 and 7 wherein the distance W ranges from 0 to 100 percent of thedistance L, but in some instances distance W is at least 0.25 of thedistance L to provide space in a proximal portion of the implant 10 forbone growth promoting material to be adequately post-packed into thearea defined at least in part by distance W when the plug 130 is moveddistally. Therefore a proximal portion of the implant 10 (such as aninternal volume defined at least in part by frame 100) may be leftsubstantially open and in fluid communication with the proximal aperture111 of the frame 100 such that a bone growth promoting material may beplaced through the proximal aperture 111 of the frame 100 after the plug130 is moved in a distal direction D (see FIG. 3 showing the plug in aninitial position, and FIG. 4 showing the plug moved distally to reveal aframe 100 volume left open and in fluid communication with the proximalaperture 111).

In other embodiments, as shown relative to the implant 20 in FIGS. 5-8 ,a single side wall 204 may replace the dual-wall embodiments of FIGS.1-4 to space the distal wall 120 of the frame 100 from the proximal wall110 of the frame. In some such embodiments with a single side wall 204,the frame 200 may be substantially open on one side of the implant 10 toallow for post-insertion packing of bone growth promoting material viathe open side of the frame 200. The “open” or wall-less side of theframe 200 (which may be positioned generally opposite the side wall 204)may also be used to direct and/or contain bone growth promoting materialthat may be introduced to the implant implantation site through theproximal aperture 211 of the frame 200 of the implant 20. As with the“closed” embodiment having two side walls 102, 104, the single side wall204 embodiments may also define internal threads 203 configured tocooperate with an outer threaded surface 231 of the plug 230 when theplug 230 is positioned generally proximally relative to the distal wall220 of the frame 200.

In various embodiments, the plug 130, 230 provided in the expandablespinal implant 10, 20 may comprise a threaded outer surface 131 (seeFIG. 1 , for example), and the distal aperture 121 may comprise acomplementary threaded inner surface operably engaged with the threadedouter surface 131 of the plug 130. The threaded outer surface 131 of theplug may be disposed on a proximal end of the plug 130 such that theplug 130 moves distally D as shown in FIG. 4 when the plug 130 isrotated relative to the distal wall 120 of the frame 100. In someembodiments, as shown generally in FIGS. 4 and 8 , the frame 100 maycomprise a sidewall 104 connecting the distal wall 120 and the proximalwall 110, wherein the at sidewall 104 comprises a sidewall threadedsurface 103 configured to be operably engaged with the threaded outersurface 131 of the plug 130 (especially when the plug is stillpositioned proximally relative to the frame 100). An alternateembodiment of the sidewall threaded surface 203 is also shown in FIG. 8. Furthermore, the plug 130 may also comprise a distal head portion 135configured to urge the endplate 140 away from the frame 100 with theplug 130 is moved in a distal direction D. The distal head portion 135may be configured in some embodiments (as shown generally in FIGS. 1-4 )with a separate structure having ramped surfaces 136 that may beconfigured to interface with complementary ramped surfaces on theendplates 140, 150. For example, as shown in FIG. 3A, the endplate 150(and the complementary endplate 140) may comprise ramped surface 153upon which ramped surface 136 of the distal head portion 135 may bear asthe implant 10 is expanded. The ramp 136/153 mechanism may cooperatewith the lateral post 137 and track 155 system in order to optimize theopening and/or expansion of the implant 10. For example, the ramp136/153 mechanism may provide a leading expansion mechanism that issubsequently assisted by the lateral post 137 and track 155 system toexpand the implant as the plug 130 is moved. Furthermore, the lateralpost 137 and track 155 system may also render the expansion of theimplant 10 reversible by pulling the endplates 140, 150 inward towardsthe frame 100 along a relatively smooth ramped incline provided by theramp 136/153 mechanism. Furthermore, the plug 130 may comprise separateconnecting elements 132, 133 such that the distal head portion 135 ofthe plug may be distally movable relative to the frame 100 withoutrotation while a proximal portion of the plug 130 (such as that portiondefining the threaded outer surface 131) is able to freely rotate in thedistal aperture 121 of the distal wall 120 of the frame 100.

In other embodiments, as shown generally in FIGS. 5-8 , the plug 230 mayinclude a distal head portion 235 comprising a tapered cylinder. In somesuch embodiments, the distal head portion 235 may be configured torotate with the plug 230 and/or move only distally D relative to theframe 100 as a proximal portion (defining the outer threaded surface231, for example) is rotated relative to the frame 100 to drive the plug230 in the distal direction D. According to some such embodiments, thedistal head portion 235 may be configured to cooperate with a contouredbearing surface 253 (comprising in some instances a ramp and/orfrusto-conical concave surface) defined on an interior surface of theendplates 240, 250.

The distal head portions 135, 235 may be configured in various ways toprovide a lead-in or gradual taper in order to allow for an easierinteraction between the plug 130, 230 and the endplates 140, 150 or 240,250. For example, as shown generally in the partially disassembled viewof FIG. 3 (where the first endplate 140, is removed), the distal headportion 135 comprises a ramp 136 or wedge suitable for urging acomplementary ramped or contoured surface 153 on the inside of theendplates 140, 150 (see FIG. 3A, showing an isolated view of oneendplate 150 with an exemplary ramp 153 formed therein) so as togradually move the endplate 140 away from the frame 100 as the plug 130is advanced distally along the length L of the implant 10. Similarly, inthe embodiments shown in FIGS. 5-8 , the distal head portion 235 may betapered to provide a lead-in or frustoconical shape that may beoptimized with a taper that allows for a mechanical advantage to berealized when urging the endplates 240, 250 away from the frame 200. Theresulting open configuration of the implant 20 is shown, for example, inFIG. 6 . Furthermore, it should be understood that a variety of rampand/or taper configurations may be used to optimize the interaction ofthe plug 130, 230 with the endplates 140, 150 or 240, 250. Suchconfigurations may include, but are not limited to: sequential ramps ortapered frustoconical surfaces with varying angles; shallow anglesequential ramps or tapered frustoconical surfaces leading into higherangle sequential ramps or tapered frustoconical surfaces (increasing themechanical advantage once an initial expansion of the implant 10 hasbeen achieved), as well as other opening mechanisms (such as the lateralpost 137 and track 155 system shown generally in FIGS. 2-4 that maycombine to assist the ramps 136 (and 153, See FIG. 3A) in expanding theimplant 20).

As shown in FIGS. 2-4 , in some embodiments of the expandable spinalimplant 10, the distal head portion 135 may comprise a lateral post 137extending from the distal head portion 135 of the plug 130 andconfigured for cooperating with a corresponding channel 145, 155 definedin the endplates 140, 150. The channels may be angled or partiallyangled to provide additional mechanisms for assisting in the expansionof the implant 10 as the plug 130 is advanced distally along the lengthL of the implant 10. Referring more particularly, to FIG. 2 , the firstendplate 140 may define at least one lateral channel 145 configured toreceive the lateral post 137 such that when the plug 130 is moved in adistal direction along the length L, the lateral post 137 of the distalhead portion 135 is moved in a first direction in the lateral channel145 to expand the first endplate 140 outward from the frame 100. Thepost 131 and channel 145 mechanism may also aid in making the implant 10expansion substantially reversible such that when the plug 130 is movedin a proximal direction (i.e. towards the distal wall 110 of the frame100) the lateral post 137 of the distal head portion 135 is moved in asecond direction in the lateral channel 145 to contract the firstendplate 140 towards the frame 100 (which may result in the implant 10returning to the closed or unexpanded configuration shown generally inFIG. 1 ). This reversible feature, combined with the threaded mechanismof the plug 130 renders the implant 10 capable of being incrementallyexpanded or contracted through a substantially infinitely adjustablerange of motion (bounded only by the length of the plug 130 and thecorresponding bearing surfaces (see 253, FIG. 6 , for example) definedby the endplates of the implant 10)).

In some embodiments, the expandable spinal implant system 10, 20 may beconfigured to be operable with and/or inserted by an insertioninstrument 30 (see generally FIG. 17 for example). In some suchembodiments, as shown in FIG. 9 , the expandable spinal implant 10 maycomprise a frame 100 comprising a proximal wall 110 and a distal wall120. The proximal wall 110 may further define a proximal aperture 111and the distal wall 110 may further define a distal aperture 121. Asdescribed herein, one or both of the proximal aperture 111 and thedistal apertures 121 may be internally threaded to receive otherthreaded components. In some embodiments, the proximal wall 110 may beadapted to receive an insertion instrument 30 (or in some cases an innercannula 320 of the insertion instrument 30 as shown in FIG. 9 ).

As described herein, the expandable spinal implant 10 may also comprisea plug 130 movably disposed in the distal aperture 121, wherein the plug130 comprises an interface 134 adapted to be operably engaged by atleast a portion of the insertion instrument 30 to move the plug 130. Forexample, in some embodiments, the insertion instrument 30 may comprise adriver shaft 330 with a driver on a distal end thereof (such as ahexalobular driver tip). The distal end of the driver shaft 330 may beengaged with the interface 134 of the plug 130 to rotate the plug in thedistal aperture 121 of the frame 100 in order to expand the implant 10.As described herein, expansion of the implant 10 may be achieved by themoving the endplates 140, 150 that are operably engaged by the frame 100and configured to move relative to the frame 100 when the plug 130 ismoved by the insertion instrument 30 (or the driver shaft 330 thereof).

As shown generally in FIG. 17 , the driver shaft 330 may be coaxiallydisposed inside an inner cannula 320 of the insertion instrument 30.Furthermore, both the driver shaft 330 and the inner cannula 320 may becoaxially disposed inside a cannula 330 of the insertion instrument 30.Each of the driver shaft 330, inner cannula 320 and cannula 310 mayfurther be provided with various manipulation components 330′, 320′ and310′ respectively, so that the various components of the insertioninstrument 30 may be operated and/or selectively manipulated independentof one another to perform various functions relative to the implant 10(as described further herein).

As described herein and shown in the embodiments of FIGS. 3 and 7 , theframe 100, 200 may further comprise at least one side wall 104, 204engaged with the proximal wall 110 and the distal wall 120 of the frame100. The side wall 104, 204 may be configured to space the proximal wall110 and the distal wall 120 of the frame 100 along a longitudinal axis(extending parallel to the length L) of the implant 10, 20. In someembodiments, as shown in FIG. 3 , the frame 100 comprises a pair of sidewalls 102, 104 spaced laterally apart and engaged with the proximal wall110 and the distal wall 120 of the frame 100 to form a substantiallyclosed area adapted to receive and/or contain a bone growth promotingmaterial that may be placed through the proximal aperture 111 of theframe 100. In some embodiments, the cannula 310 or inner cannula 320 ofthe insertion instrument 30 may be configured to convey bone growthpromoting material through the insertion instrument 30 and into the areadefined by the frame 100 when the implant 10 is in the expanded position(see FIG. 2 , for example, showing the plug 130 moved distally forwardand out of the proximal area of the implant 10 defined by the frame100).

In some embodiments the frame 100 may be substantially “closed” withsidewalls as shown generally in FIGS. 9-12 . In other embodiments, theframe 100 may comprise a pair of sidewalls 102, 104 with lateralapertures as shown generally in FIGS. 1-4 . In other embodiments, asshown generally in FIGS. 5-8 , the frame 200 may comprise a unilateralor single side wall 204 forming a frame 200 with one “open” lateralside. In some such embodiments as shown in FIG. 8 , the frame 200 may beadapted to an least partially contain a bone growth promoting materialBG that may be placed through the proximal aperture 211 of the frame 200and/or direct the bone growth promoting material BG outside of theexpandable spinal implant 20 in a lateral direction between the proximalwall 210 and the distal wall 220 of the frame 200.

FIGS. 9-12 show various configurations of an implant 10 embodiment inuse with an insertion instrument 30 to form an expandable spinal implantsystem according to one embodiment. As shown generally in FIG. 9 , thesystem may comprise an insertion instrument 30 comprising a cannula 310(which may include an inner cannula 320 and an outer cannula 310 asdescribed herein) and a driver shaft 330 (see FIG. 10 and FIG. 17 )removably and rotatably disposed within the cannula 310. The system mayalso further comprise an expandable spinal implant 10 configured to beoperably engaged with the insertion instrument 30 using a variety ofmechanisms. As described herein, the implant 10 comprises a frame 100comprising a proximal wall 110 and distal wall 120, wherein the proximalwall 110 defines a proximal aperture 111 and the distal wall 120 definesa distal aperture. The proximal wall 110 may be configured to receive adistal end of the cannula 310 (or the middle cannula 320) formanipulating the expandable spinal implant 10. For example, as shown inFIG. 9 , the cannula 310 may comprise prongs 311 configured forinsertion into complementary receptacles 114 defined by the proximalwall 110 of the frame 100. In other embodiments, the prongs 311 mayinteract with tabs or slots defined by the endplates 140, 150. Theprongs 311 may interact with the receptacles 114 to enable a surgeon tomanipulate the implant 10 effectively as it is engaged with a distal endof the insertion instrument. Furthermore, in some embodiments, the innercannula 320 may comprise a threaded tip 321 configured for operablyengaging threaded inner surface of the proximal aperture 111 of theframe 100. In some such embodiments, the prongs 311 of the outer cannulamay serve as an effective counter-torque device (preventing rotation ofthe implant 10 relative to the insertion instrument 30) as the innercannula 320 is rotated to engage the proximal aperture 111 of the frame100. FIG. 17 shows the insertion instrument 30 in relation to theimplant 10 including manipulation components 330′, 320′ and 310′ of theinsertion instrument. For example, handle 310′ of the outer cannula 310may be used to stabilize and/or manipulate the implant 10 even as theknob 320′ of the inner cannula 320 is rotated within the outer cannula310 such that the threaded tip 321 may be engaged with the proximalaperture 111 of the frame 100 without rotating the implant 100.

As described herein, the implant 10 may be configured for expansion byvirtue of a plug 130 movably disposed in the distal aperture 120 of theframe 100. In some embodiments, the plug comprises a threaded outersurface 131 configured to be engaged with a complementary inner threadedsurface of the distal aperture 120. In some embodiments, as shown inFIG. 9 , the plug 130 may comprise an interface 134 configured to beoperably engaged by a distal end of a driver shaft 330 to move (bythreaded rotation, for example) the plug 130 relative to the frame. Thedriver shaft 330 may be coaxially placed within the cannula 310 and/orthe inner cannula 310 and rotatable therein using the driver proximalend 330′ of the driver shaft 330. The driver proximal end 330′ maycomprise a keyed or faceted surface configured for engagement with aquick-release handle (not shown) or a powered driver (not shown) forrotating the driver shaft 330. Furthermore, the plug interface 134 maycomprise a drive receptacle configured to cooperate with a distal end ofthe driver shaft. The drive connection between the driver shaft 330 andthe plug interface 134 may comprise a variety of drive interfacesincluding but not limited to: multi-lobular drives; hexalobular drives;cross or Phillips head drives; straight or “flat head” drives; square orother polygonal drives; and/or combinations thereof.

As described herein, the movement of the plug 130 facilitated by thedriver shaft 310 within the cannula 310 (and, in some cases the innercannula 320) may further cause the movement of an endplate 140, 150operably engaged with the frame 100 of the implant 10 relative to theframe 100 when the plug 130 is moved by the insertion instrument 30.Thus the insertion instrument 30 (or the driver shaft 330 and driverproximal end 330′) may be used to expand the endplates 140, 150 relativeto the frame 100 in order to selectively expand the implant 10 and/orimpart a lordotic movement in adjacent vertebral bodies V1, V2 as showngenerally in FIGS. 14 and 16 . The length of the driver shaft 330 may beadjusted to account for the distal placement of the distal wall 120 ofthe frame 100 relative to the length L of the implant 10. For example,the driver shaft 330 may be provided with a length that substantiallyexceeds that of the cannula 310 and/or inner cannula 320 so that thedriver proximal end 330′ remains accessible and engaged with a handle orpowered driver even when the driver shaft 330 remains engaged with theplug 130 of the implant 10 when the implant is in the fully expandedcondition (see FIGS. 14 and 16 ). This feature may be important insituations where a surgeon wishes to reverse the expansion of theimplant 10 as described further herein with respect to the post 131 andchannel 145 mechanisms of particular implant 10 embodiments.

According to various embodiments, the driver shaft 330 may also beconfigured to be removable from the cannula 310 (and/or the innercannula (if employed)), such that after the plug 130 of the implant 10has been moved distally relative to the frame 100, a bone growthpromoting material BG may be introduced into the frame 100 of theexpandable spinal implant 10 through the cannula 310 (and/or through theconcentric inner cannula 320, when used). The bone growth promotingmaterial BG may be tamped or urged through the cannula 310 or innercannula 310 using the driver shaft 330 or other tamp and/or rod (notshown) sized for slidable insertion through the cannula 310 and/or innercannula 310. A funnel (not shown) or other attachment may also beinserted into a proximal end of the cannula 310 or inner cannula 320(such as at the point near the proximal end or knob 320′ of innercannula 320, as shown in FIG. 17 ) to facilitate the introduction of thebone growth promoting material BG into the cannula 310 and/or innercannula 320.

FIGS. 9-12 depict exemplary procedural steps for the use of the implantsystem in one embodiment. For example, FIG. 9 shows an unexpandedimplant 10 attached to insertion device 30 using the prongs 311 of thecannula 310 and the distal end 321 of inner cannula 320. The plug 130 isshown engaged with the distal aperture of distal wall 120 of the frameand the plug interface 134 is visible. In FIG. 10 , the driver shaft 330is shown extended through cannula 310 and inner cannula 320 and engagedwith the plug interface 134. Referring to FIG. 17 , the driver proximalend 330′ may be rotated at this step to drive the plug 130 forward toexpand the endplates 140, 150 relative to the frame 100. FIG. 11 showsthe result of the interaction of the driver shaft 330 with the plug 130and the distal movement of the plug 130 relative to the distal wall 120of the frame 100 to expand the endplates 140, 150 relative to the frame100 of the implant 10. FIG. 12 shows the insertion device 30 stillengaged with the implant 10 but with the driver shaft 330 removed fromthe cannula 310 and inner cannula 320, leaving the cannulas open for theintroduction of bone growth promoting material BG through the insertioninstrument 30 and into a proximal portion of the implant 10 definedgenerally by the now-open interior of the frame 100.

Referring to exemplary FIGS. 13-16 , spinal implant system 10, 30 can beemployed with a surgical arthrodesis procedure, such as, for example, aninterbody fusion for treatment of an applicable condition or injury ofan affected section of a spinal column and adjacent areas within a body,such as, for example, intervertebral disc space between a vertebra V1and a vertebra V2. In some embodiments, spinal implant system 10, 30 caninclude an intervertebral implant that can be inserted withintervertebral disc space to space apart articular joint surfaces,provide support and maximize stabilization of vertebrae V1, V2. In someembodiments, spinal implant system 10, 30 may be employed with one or aplurality of vertebra.

A medical practitioner obtains access to a surgical site includingvertebrae V1, V2 such as through incision and retraction of tissues.Spinal implant system 10, 30 can be used in any existing surgical methodor technique including open surgery, mini-open surgery, minimallyinvasive surgery and percutaneous surgical implantation, wherebyvertebrae V1, V2 are accessed through a mini-incision, retractor, tubeor sleeve that provides a protected passageway to the area. In oneembodiment, the components of spinal implant system 10, 30 are deliveredthrough a surgical pathway to the surgical site along a surgicalapproach into intervertebral disc space between vertebrae V1, V2.Various surgical approaches and pathways may be used. FIG. 13 shows anexample of a typical posterior lumbar interbody fusion (PLIF) approachusing the spinal implant system 10, 30 wherein a pair of implants 10 maybe delivered, expanded to impart or restore a lordotic curve (seegenerally FIG. 14 ), and then post-packed with bone growth promotingmaterial BG after the removal of the driver shaft 330 from the insertioninstrument 30. As shown in FIG. 15 , unilateral approaches such as atransforaminal lumbar interbody fusion (TLIF) approach may also be usedto place the implant in a substantially oblique position relative to thevertebrae V1, V2. In such procedures the distal end 144 of the endplates140, 150 may be shaped so that the implant 10 fits within theintervertebral space defined by the extents of the vertebral body V2 asshown in FIG. 15 . Furthermore, in oblique placement applications theimplant 10 endplates 140, 150 may also be provided with complementaryoblique contact surfaces shaped to better impart and/or restore alordotic curve as the implant 10 is expanded as shown generally in FIG.16 . Furthermore, the endplates 140, 150 of the implant may be providedwith a variety of ridges, teeth, coatings or other surface treatmentssuitable for interacting with and/or securing relative to the adjacentvertebrae V1, V2.

As will be appreciated by one of skill in the art, a preparationinstrument (not shown) may be employed to remove disc tissue, fluids,adjacent tissues and/or bone, and scrape and/or remove tissue fromendplate surfaces of vertebra V1 and/or endplate surface of vertebra V2in preparation for the procedures utilizing the system 10, 30. In someembodiments, the size of implant 10 is selected after trialing usingtrialing instruments (not shown) that may approximate the size andconfiguration of the system 10, 30 (as shown in FIG. 17 , for example).In some embodiments, such trials may be fixed in size and/or be fittedwith expansion mechanisms similar to the various implant 10, 20embodiments described herein. In some embodiments, implant 10 may bevisualized by fluoroscopy and oriented before introduction intointervertebral disc space. Furthermore, the insertion instrument 30 andimplant 10 may be fitted with fiducial markers to enable image guidedsurgical navigation to be used prior to and/or during a procedure.

In some embodiments as shown generally in FIGS. 13 and 15 , implant 10provides a footprint that improves stability and decreases the risk ofsubsidence into tissue. In some embodiments as shown generally in FIGS.14 and 16 , implant 10 provides angular correction, height restorationbetween vertebral bodies, decompression, restoration of sagittal and/orcoronal balance and/or resistance of subsidence into vertebralendplates. In some embodiments, implant 10 engages and spaces apartopposing endplate surfaces of vertebrae V1, V2 and is secured within avertebral space to stabilize and immobilize portions of vertebrae V1, V2in connection with bone growth for fusion and fixation of vertebrae V1,V2.

Components of spinal implant system 10, 30 including implant 10 can bedelivered or implanted as a pre-assembled device or can be assembled insitu. Components of spinal implant system 10, 30 including implant 10may be expanded, contracted, completely or partially revised, removed orreplaced in situ. In some embodiments, one or all of the components ofspinal implant system 10, 30 can be delivered to the surgical site viamechanical manipulation and/or a free hand technique.

In one embodiment, spinal implant system 10, 30 includes a plurality ofimplants 10 (see FIG. 13 for one example). In some embodiments,employing a plurality of implants 10 can optimize angular correctionand/or height restoration between vertebrae V1, V2 The plurality ofimplants 10 can be oriented in a side by side engagement, spaced apartand/or staggered.

In some embodiments, spinal implant system 10, 30 includes an agent,including but not limited to the bone growth promoting materials BGdescribed herein, which may be disposed, packed, coated or layeredwithin, on or about the components and/or surfaces of spinal implantsystem 10, 30. In some embodiments, the agent may include bone growthpromoting material to enhance fixation of implant 10 with bonystructures. In some embodiments, the agent may include one or aplurality of therapeutic agents and/or pharmacological agents forrelease, including sustained release, to treat, for example, pain,inflammation and degeneration.

In one embodiment, implants 10, 20 may include fastening elements, whichmay include locking structure, configured for fixation with vertebraeV1, V2 to secure joint surfaces and provide complementary stabilizationand immobilization to a vertebral region. In some embodiments, lockingstructure may include fastening elements, such as, for example, rods,plates, clips, hooks, adhesives and/or flanges. In some embodiments, thecomponents of spinal implant system 10, 30 can be used with screws toenhance fixation. The components of spinal implant system 10 can be madeof radiolucent materials such as polymers. Radiopaque markers may beincluded for identification under x-ray, fluoroscopy, CT or otherimaging techniques. The insertion instrument 30 alone or with the tubefor insertion therethrough described above may be radiolucent and mayoptionally include markers added at the distal tip and/or along thelength of one or both of insertion instrument 30 and the tube to permitthem to be seen on fluoroscopy/x-ray while advancing into the patient.If the implant 10 includes radiolucent markers placed near the proximalend this may permit visualization of the proximity of the tip of thetube moving toward the proximal end of the implant 10.

In one embodiment of the invention, the endplates 140 and 150 include ananterior portion 400 extending to one side of the implant from one sideonly of respective lateral surfaces at the respective distal ends of theendplates 140 and 150. The anterior portion 400 extends along an axis1-1, which extends transverse to the central longitudinal axis CL.Anterior portion 400 ends in an anterior tip 402. As depicted in FIGS.19-23 and 27-32 , when the implant is in the collapsed position, theanterior portion 400 and the anterior tip 402 define a distal end hookedportion 404. When the implant is in the collapsed position, the distalend of the first endplate 140 combines with the distal end of the secondendplate 150 to define a distal end beveled portion 406. The distal endhooked portion 404 provides each of the endplates 140/150 with anincreased surface area, enabling them to withstand greater loads duringimplant expansion, and to create lordosis.

In one embodiment of the invention, at least the distal end hookedportion 404 is configured, as depicted in FIGS. 23 and 35 , uponinsertion of the implant 10 into a disc space between an upper vertebralbody and a lower vertebral body, to hook around the vertebral foramenVF, thereby avoiding interference with the neural elements, particularlythe spinal cord, located in the vertebral foramen.

In one embodiment of the invention, at least the distal end hookedportion 404 is further configured, as depicted in FIG. 36 , uponinsertion of the implant into the disc space, to rotate from a laterallydivergent pathway to a TLIF/transverse pathway.

In one embodiment of the invention, as depicted in FIGS. 24-26 , theimplant 10 is configured to be inserted into the disc space until thedistal end hooked portion 404 and the distal end beveled portion 406engage an entire portion of the anterior apophyseal rims of each of theupper and lower vertebral bodies. As depicted in FIG. 33 , the distalend hook portion 404 and the distal beveled end portion 406 engage theanterior apophyseal rim, while a proximal end corner 408 contacts theposterior rim.

In one embodiment of the invention, as depicted in FIG. 29 , the distalend hooked portion 404 and the distal end beveled portion 406 continueto engage entirely along apophyseal rims of each of the upper and lowervertebral bodies following expansion of the implant.

In one embodiment of the invention, as depicted in FIGS. 27-32 , anupper surface 410 of the frame 100 includes first parallel rows of teeth412. A lower surface 414 of the frame 100 includes second parallel rowsof teeth 416. As depicted in FIGS. 27-32 , at least an upper surface 418of the first endplate 140 includes third rows of teeth 420, definedparallel to the first rows of teeth 412. Fourth rows of teeth 422 aredefined at least on the lower surface 421 of second endplate 150 in anorientation parallel to the first rows of teeth 412.

In one embodiment of the invention, as depicted in FIGS. 27-32 , analternative embodiment of third rows of teeth 420′ can be provided onthe upper surface 418 of first endplate 140 in an orientationperpendicular to the first rows of teeth 412. Likewise an alternativeembodiment of fourth rows of teeth 422′ can be provided on lower surface421 of the second endplate 150 perpendicular to the distal end beveledportion 406. Perpendicular third rows of teeth 420′ and fourth rows ofteeth 422′ provide improved purchase against the vertebral bone of theanterior apophyseal rims when the implant 10 is in the expandedposition. In addition, when the implant is in the expanded position,first rows of teeth 412, second rows of teeth 416, third rows of teeth420, fourth rows of teeth 422, and alternate third rows of teeth 420′and fourth rows of teeth 422′ all are configured to prevent inadvertentbackout of the implant 10 from the anterior apophyseal rims of the upperand lower vertebral bodies. Although FIGS. 27-32 depict the respectivesurfaces of the endplates fully covered by the rows of teeth 420, 422,420′, and 422′, it is within the scope of the invention for these rowsof teeth to only partially cover the surfaces of the endplates.

In one embodiment of the invention, as depicted in FIG. 31 , a width W1of the implant 10 at the distal end hooked portion 404 is greater than awidth W2 of the implant 10 at the frame proximal wall 110, therebyproviding increased structural strength at the distal end hooked portion404.

In one embodiment, as depicted in FIG. 37 , the distal end hookedportion 404 is configured to be positioned in the disc space between theupper and lower vertebral bodies at a position crossing the midline MLof the disc space.

In one embodiment of the invention, as depicted in FIG. 38 , the distalend hooked portion 404 is configured to be positioned in the disc spacebetween the upper and lower vertebral bodies at a position spacedlaterally to one side of the midline ML of the disc space.

In one embodiment of the invention, as depicted in FIG. 39 , a pair ofexpandable implants 10 is configured to be positioned in the disc spacebetween the upper and lower vertebral bodies, each respective implant 10being located at a position spaced laterally to opposite sides of themidline ML of the disc space.

In one embodiment of the invention, as depicted in FIG. 31 the endplatesinclude opposing respective sidewalls 423/424. The endplate sidewalls423/424, with the frame sidewalls 102/104 and the proximal wall 110define an enclosed area to hold bone growth material inserted into theimplant 10 via the proximal aperture 111.

In one embodiment of the invention, as depicted in FIG. 29 , the distalhead 135 of the plug 130 abuts against a distal wedge portion 426. Asthe distal wedge portion 426 is pushed toward the proximal end of theimplant 10, it pivots the first endplate 140 away from the secondendplate 150, expanding the implant 10 to the expanded position.

In one embodiment of the invention, as depicted in FIGS. 31-39 , thedistal end beveled portion 406 intersects with one of the side walls423/424 of the frame 100 opposite the distal end hooked portion 404,defining a distal end arcuate portion 428. The distal end arcuateportion 428 and the distal end beveled portion 406 together reduce aprofile of insertion into the disc space of the implant 10.

In one embodiment of the invention, as depicted in FIG. 33 , the distalend arcuate portion 428 allows the implant 10 to obtain greater lateralbony contact which is closer to the harder lateral vertebral rim, and toprovide a greater medial grafting area.

In one embodiment of the invention, as depicted in FIGS. 40 and 41 , theorientation of the distal end hooked portion 404 is reversed to extendfrom the opposite side of the implant 10. In this embodiment, asdepicted in FIG. 41 , the implant 10 contacts both the anterior rim andthe posterior rim, providing improved stabilization of the adjacentvertebral bodies.

In some embodiments, the use of microsurgical, minimally-invasive andimage guided technologies may be employed to access, view and repairspinal deterioration or damage, with the aid of spinal implant system10, 30. Upon completion of the procedure, the non-implanted components,surgical instruments and assemblies (such as insertion instrument 30) ofspinal implant system 10, 30 may be removed and the incision is closed.In some embodiments, the various instruments (such as the insertioninstrumentation disclosed generally herein in FIG. 9 and relatedfigures) disclosed may be provided with fiducial markers or otherelements suitable for use with surgical navigation systems (including,but not limited to the STEALTHSTATION® Navigation system available fromMedtronic plc), such that a surgeon may view a projected trajectory orinsertion pathway of the implants 10, 20 relative to a patient's anatomyin real time and/or in near-real time.

It will be understood that the various independent components of theexpandable spinal implants 10, 20, systems and insertion instruments 30described herein may be combined in different ways according to variousembodiments. As a non-limiting example, the notches 114 shown in FIGS.5-8 with respect to implant 20 may also be added to a proximal end ofthe implant 10 shown in FIGS. 1-4 . As a further non-limiting example,the dual apertures 241 a, 241 b, 251 a, 251 b shown in FIGS. 5-8 withrespect to the endplates 240, 250 of implant 20, may also be added tothe endplates 140, 150 of the implant 10 shown in FIGS. 1-4 .

It will be understood that various modifications may be made to theembodiments disclosed herein. Other embodiments of the invention will beapparent to those skilled in the art from consideration of thespecification and practice of the invention disclosed herein. It isintended that the specification and examples be considered as exemplaryonly, with the true scope and spirit of the invention being indicated bythe following claims.

What is claimed is:
 1. An expandable spinal implant comprising: a framecomprising a frame proximal end, an opposite frame distal end, a distalwall at the frame distal end, and a distal aperture defined in thedistal wall; a plug movably disposed in the distal aperture andconfigured for movement from a first position to a second position, theplug including a head portion including at least a first lateral postportion and a second lateral post portion; a first endplate portionpivotally engaged with the frame and configured to expand outward fromthe frame when the plug is moved from the first position to the secondposition, the first endplate portion including an upper surface, a firstendplate portion proximal end, a first endplate portion distal end, atleast one of a first endplate portion first lateral surface extendingbetween the first endplate portion proximal end and the first endplateportion distal end and an opposing first endplate portion second lateralsurface extending between the first endplate portion proximal end andthe first endplate portion distal end, and a first channel formed in theat least one of the first endplate portion first lateral surface and thesecond endplate portion second lateral surface, the first channel beingconfigured to receive one of the first lateral post portion and thesecond lateral post portion; a first distal end portion extendingoutwardly from the first endplate portion including at least one sidesurface and a first tip portion, the at least one side surface of thefirst distal end portion extending from the first tip portion to the atleast one of the first endplate portion first lateral surface and thefirst endplate portion second lateral surface; a second endplate portionpivotally engaged with the frame and configured to expand outward fromthe frame when the plug is moved from the first position to the secondposition, the second endplate portion including a lower surface, asecond endplate portion proximal end, a second endplate portion distalend, at least one of a second endplate portion first lateral surfaceextending between the second endplate portion proximal end and thesecond endplate portion distal end and an opposing second endplateportion second lateral surface extending between the second endplateportion proximal end and the second endplate portion distal end, and asecond channel formed in the at least one of the second endplate portionfirst lateral surface and the second endplate portion second lateralsurface, the second channel being configured to receive the other of thefirst lateral post portion and the second lateral post portion; a seconddistal end portion extending outwardly from the second endplate portionincluding at least one side surface and a second tip portion, the atleast one side surface of the second distal end portion extending fromthe second tip portion to the at least one of the second endplateportion first lateral surface and the second endplate portion secondlateral surface; wherein movement of the plug from the first position tothe second position, and corresponding interaction of the one of thefirst lateral post portion and the second lateral post portion in thefirst channel causes the first endplate portion and the first distal endportion to move away from the frame and interaction of the other of thefirst lateral post portion and the second lateral post portion in thesecond channel causes the second endplate portion and the second distalend portion to move away from the frame to move the implant from acollapsed position to an expanded position; and wherein the first distalend portion includes a mid-longitudinal axis that is transverse to amid-longitudinal axis of the first endplate portion, and the seconddistal end portion includes a mid-longitudinal axis that is transverseto a mid-longitudinal axis of the second endplate portion.
 2. Theexpandable spinal implant of claim 1, wherein when the implant is in thecollapsed position, the first tip portion and the second tip portionfurther define a distal end beveled portion.
 3. The expandable spinalimplant of claim 2, wherein the implant is configured to be inserted ina disc space between upper and lower vertebral bodies until the distalend beveled portions engage anterior apophyseal rims of each of theupper and lower vertebral bodies.
 4. The expandable spinal implant ofclaim 1, wherein at least one of the first endplate upper surface and anupper surface of the first distal end portion comprises at least onefirst row of teeth defined thereon, and the second endplate lowersurface and at least one of a lower surface of the second distal endportion comprises at least one second row of teeth defined thereon. 5.The expandable spinal implant of claim 1, wherein the frame furthercomprises a proximal wall at the frame proximal end, and at least oneframe side wall engaged with the frame proximal wall and the framedistal wall, the frame side wall configured to space the frame proximalwall and the frame distal wall along a longitudinal axis of theexpandable spinal implant.
 6. The expandable spinal implant of claim 5,wherein the plug comprises a threaded outer surface, and wherein thedistal aperture comprises a threaded inner surface operably engaged withthe threaded outer surface of the plug.
 7. The expandable spinal implantof claim 1, wherein the head portion of the plug is configured tocontact portions of the first endplate portion and the second endplateportion to aid movement of the first endplate portion and the secondendplate portion away from the frame when the plug is moved from thefirst position to the second position.
 8. The expandable spinal implantof claim 1, wherein one of the first endplate portion and the secondendplate portion further comprise a first lateral side wall and a secondlateral side wall spaced laterally apart from one another, the firstlateral side wall extending in a first plane, the second lateral sidewall extending in a second plane, and at least portions of the firstdistal end portion and the second distal end portion being locatedoutside of the area between the first plane and the second plane.
 9. Anexpandable spinal implant comprising: a frame comprising a frameproximal end, an opposite frame distal end, a distal wall at the framedistal end, and a distal aperture defined in the distal wall; a plugmovably disposed in the distal aperture and configured for movement froma first position to a second position, the plug including a head portionincluding at least a first lateral post portion and a second lateralpost portion; a first endplate portion pivotally engaged with the frameand configured to expand outward from the frame when the plug is movedfrom the first position to the second position, the first endplateportion including an upper surface, an inner surface, a first endplateportion proximal end, a first endplate portion distal end, and a firstchannel formed in the first endplate portion, the first channel beingconfigured to receive one of the first lateral post portion and thesecond lateral post portion; a first distal end portion extendingoutwardly from the first endplate portion including a first sidesurface, a second side surface, and a first tip portion, at least one ofthe first side surface and the second side surface of the first distalend portion extending from the first tip portion to the first endplateportion; a second endplate portion pivotally engaged with the frame andconfigured to expand outward from the frame when the plug is moved fromthe first position to the second position, the second endplate portionincluding a lower surface, an inner surface, a second endplate portionproximal end, a second endplate portion distal end, and a second channelformed in the second endplate portion, the second channel beingconfigured to receive the other of the first lateral post portion andthe second lateral post portion; a second distal end portion extendingoutwardly from the second endplate portion including a first sidesurface, a second side surface, and a second tip portion, at least oneof the first side surface and the second side surface of the seconddistal end portion extending from the second tip portion to the secondendplate portion; wherein the first channel extends from a positionadjacent the inner surface of the first endplate portion to a positionspaced apart from the inner surface of the first endplate portion, andthe second channel extends from a position adjacent the inner surface ofthe second endplate portion to a position spaced apart from the innersurface of the second endplate portion, and movement of the plug fromthe first position to the second position, and corresponding interactionof the one of the first lateral post portion and the second lateral postportion in the first channel causes the first endplate portion and thefirst distal end portion to move away from the frame and interaction ofthe other of the first lateral post portion and the second lateral postportion in the second channel causes the second endplate portion and thesecond distal end portion to move away from the frame to move theimplant from a collapsed position to a expanded position; and whereinthe first distal end portion includes a mid-longitudinal axis that istransverse to a mid-longitudinal axis of the first endplate portion, andthe second distal end portion includes a mid-longitudinal axis that istransverse to a mid-longitudinal axis of the second endplate portion.10. The expandable spinal implant of claim 9, wherein the implant isconfigured to be inserted in a disc space between upper and lowervertebral bodies until the distal end beveled portions engage anteriorapophyseal rims of each of the upper and lower vertebral bodies.
 11. Theexpandable spinal implant of claim 9, wherein at least one of the firstendplate upper surface and an upper surface of the first distal endportion comprises at least one first row of teeth defined thereon, andthe second endplate lower surface and at least one of a lower surface ofthe second distal end portion comprises at least one second row of teethdefined thereon.
 12. The expandable spinal implant of claim 9, whereinthe frame further comprises a proximal wall at the frame proximal end,and at least one frame side wall engaged with the frame proximal walland the frame distal wall, the frame side wall configured to space theframe proximal wall and the frame distal wall along a longitudinal axisof the expandable spinal implant.
 13. The expandable spinal implant ofclaim 12, wherein the plug comprises a threaded outer surface, andwherein the distal aperture comprises a threaded inner surface operablyengaged with the threaded outer surface of the plug.
 14. The expandablespinal implant of claim 9, wherein the head portion of the plug isconfigured to contact the inner surfaces of the first endplate portionand the second endplate portion to aid movement of the first endplateportion and the second endplate portion away from the frame when theplug is moved from the first position to the second position.
 15. Theexpandable spinal implant of claim 9, wherein at least one of the firstendplate portion and the second endplate portion further comprise afirst lateral side wall and a second lateral side wall spaced laterallyapart from one another, the first lateral side wall extending in a firstplane, the second lateral side wall extending in a second plane, and atleast portions of the first distal end portion and the second distal endportion being located outside of the area between the first plane andthe second plane.
 16. An expandable spinal implant comprising: a framecomprising a frame proximal end, an opposite frame distal end, a distalwall at the frame distal end, and a distal aperture defined in thedistal wall; a plug including a head portion being moveable from a firstposition to a second position, and including at least one lateral postportion; a first endplate portion engaged with the frame, the firstendplate portion including an upper surface, a first endplate portionproximal end, a first endplate portion distal end; a first distal endportion extending outwardly from the first endplate portion including afirst side surface, a second side surface, and a first tip portion, atleast one of the first side surface and the second side surface of thefirst distal end portion extending from the first tip portion to thefirst endplate portion; a second endplate portion engaged with theframe, the second endplate portion including a lower surface, a secondendplate portion proximal end, a second endplate portion distal end; asecond distal end portion extending outwardly from the second endplateportion including a first side surface, a second side surface, and asecond tip portion, at least one of the first side surface and thesecond side surface of the second distal end portion extending from thesecond tip portion to the second endplate portion; wherein at least oneof the first endplate portion and the second endplate portion ispivotally attached to the frame, and includes at least one lateralsurface and at least one channel formed in the at least one lateralsurface; wherein the at least one channel is configured to receive theat least one lateral post, and movement of the plug from the firstposition to the second position, and corresponding interaction of the atleast one lateral post portion in the at least one channel causesmovement of the implant from a collapsed position to an expandedposition; and wherein the first distal end portion includes amid-longitudinal axis that is transverse to a mid-longitudinal axis ofthe first endplate portion, and the second distal end portion includes amid-longitudinal axis that is transverse to a mid-longitudinal axis ofthe second endplate portion.
 17. The expandable spinal implant of claim16, wherein the first distal end portion and the second distal endportion are each formed as a hooked end portion.
 18. The expandablespinal implant of claim 16, wherein one of the first endplate portionand the second endplate portion further comprise a first lateral sidewall and a second lateral side wall spaced laterally apart from oneanother, the first lateral side wall extending in a first plane, thesecond lateral side wall extending in a second plane, and at leastportions of the first distal end portion and the second distal endportion being located outside of the area between the first plane andthe second plane.
 19. The expandable spinal implant of claim 16, whereinthe frame further comprises a proximal wall at the frame proximal end,and at least one frame side wall engaged with the frame proximal walland the frame distal wall, the frame side wall configured to space theframe proximal wall and the frame distal wall along a longitudinal axisof the expandable spinal implant.
 20. The expandable spinal implant ofclaim 19, wherein the plug comprises a threaded outer surface, andwherein the distal aperture comprises a threaded inner surface operablyengaged with the threaded outer surface of the plug.